The text provides a comprehensive guide on generating a backend application from an API definition, highlighting its importance as a blueprint for software development. It describes the role of API definitions in detailing available endpoints, request types, and expected responses, using formats like OpenAPI, RAML, and API Blueprint for consistency. The guide advocates automating backend generation to save time, reduce errors, and maintain consistency, introducing tools such as Blackbird and OpenAPI Generator to facilitate this process. It also covers the preparation of API definitions, generating boilerplate code, and implementing business logic, using examples like a to-do list app to illustrate key steps. Furthermore, the text touches on connecting to databases, ensuring security, testing, and deploying the backend using platforms like Render, emphasizing the efficiency and reliability of using automated tools in backend development.